My two cents will come in the form of positing that the show has backed away from the H/W relationship because it was getting too, well, H/W: the only natural progression of the relationship at this point would be to actually put them together and make them canon. :) They've set up H/W as being more than just best buds; they're too intense with each other for that.

This point makes a lot of sense to me. Where can H & W possibly go from here on? They're too close, too possessive of each other. Like you said, they're too intense.

WE SEE RIGHT THROUGH YOU, WRITERS! DON'T FIGHT THE H/W LOVE! IT'S TIME FOR THEM TO COME OUT OF THE CLOSET! :D

Yes, exactly! Now is the time for H/W to take the plunge! Deny your true feelings no longer, TPTB! You know you want to! ;)